Rattling sound on iPhone5

I've read that iPhones in general have a rattling sound due to the camera. I've zoomed in while taking a picture to see if the rattling sound would stop but it seems like it's still there. The sound is only audible in a quiet room when you either shake the phone in any direction or placing the phone down onto a desk.

I recorded myself shaking the iPhone 5 in all directions, and you can hear the rattling sound. Yes I've held down the lock button and it still makes the same sound.

http://www.youtube.com/watch?v=K6Vp2FHKx2E

Is this normal? I have an iPhone 4 and the rattling sound is harder to hear when in a quiet room.